Use of Sequential Testing to Prescreen Prospective Entrants into Military Service.

Weitzman, R. A.

The goal of this research was to predict from a recruit's responses to the Armed Services Vocational Aptitude Battery (ASVAB) items whether the recruit would pass the Armed Forces Qualification Test (AFQT). The data consisted of the responses (correct/incorrect) of 1,020 Navy recruits to 200 items of the ASVAB together with the scores of these recruits on the AFQT, which functioned as the criterion. Each failure rate was used in each of three studies exemplifying three methods of item selection. Although every recruit took the entire battery, computer runs simulated the sequential procedure by selecting one item at a time. In two of the three studies the order of item selection corresponded directly to the ranking of the correlations between item responses and AFQT scores. In the first study the correlation was a point-biserial coefficient (Method 1); in the second, it was a phi coefficient, with AFQT scores dichotomized at the failure-rate centiles to maximize item discriminability (Method 2). The third study used, as an objective function for each candidate item, the ratio of the largest partial correlation between the candidate item and each item already selected, controlling for the AFQT, to the point-biserial coefficient used in Method 1. (PN)